DSA-009-1 stunnel -- insecure file handling, format string bug

Lez discovered a format string problem in stunnel (a tool
to create universal SSL tunnel for other network daemons). Brian Hatch
responded by stating he was already preparing a new release with multiple
security fixes:

The PRNG (pseudo-random generated) was not seeded correctly. This only
affects operation on operating systems without a secure random generator (like
Linux).

Pid files were not created securely, making stunnel vulnerable to a symlink attack.

There was an insecure syslog() call which could be exploited if the user
could manage to insert text into the logged text. At least one way to exploit
this using faked identd responses was demonstrated by Lez.